Stop motion for knitting machines



Nov. 25, 1930. D. F, SULLlVAN ,7 5

STOP MOTIDN FOR KNITTING MACHINES Filed July 13, 1929 Ddniel Fsulli'vcm AYTys.

a UNITED ESTA 'rfes SP E DANIEL F. SULLIVAN,

the parts 1n normal operating position;

Patented Nov. 25,1930

NTWOFFI'CE or LOWELL, MASSACHUSETTS, ASSIGNOR or ONE-HALF T0 JOHN r. runny, orv LOWELL, MAssnoHUsETTs pplication filed Ju1y 13,

This invention relates toa stop motion for knitting machines and has for its general obj eat to provide a stop motion which'is simple in construction, which can be easilyand inexpensively made and which will be effective in operation. Y f

In order to. give an understand l g f the invention I have illustrated in thedrawings a selected embodiment thereof which will. now be described after which -the novel features will. bepointed outin the appended 1 claims.

Fig, l isfa' front view of the stop motion with parts brokenout; h

F'g'. 2 is a seotionon theline 22 showing 'Fig. 3 is an enlarged'fragmentary sectional view on substantially the line 22 but illu's trating the manner in which the stop motion operates whenthe yarn breaks or becomes un i Fig. 4 is viewillustrating a thread' releasing device,which freleases the thread thereby permitting the stopjmotion to act whenever the threadbecome's undulytaut. 5

Inasmuch 1 as my present invention relates "simply to the stop motion I have not thought 1 it necessary to illustrate the knittingmachine but have confined the motion features; 1

.In the drawings 1 indicates I partoflthe frame of afknittingmachine on which is supported one or morefbobbins-QQ The yarn is drawn off from thebobbin 2- man upward vertical direction and. after passing 'through "ag'uidesecured to the frame above the bobbin the yarn passes down to the. knitting point, thisbeing the usual construction. My improved stop motion is arranged to act on the yarn between the bobbin and the upper guide and isarrange'd so that if tlie yarn breaks or becomes unduly slack the knitting machine will be stopped.

The improved stop, motion isgalso constructed so that if .the yarn as itcomes from the bobbincontains aknot orlbunchztlie knittinglmachine will be stopped beforethe knot, bunch? 0r. imperfect sectionof yarn reaches the knitting point, I j T e cha smjie n n fih kni drawings to the stop STOP-MOTION non KNITTING MACHINES 1923. Serial m.- 77,999.}.

stop the knitting machine eitherby releasing the shipper rod or by throwing out the clutch or in any other way commonly employed in knittingmachines. For the present purposes it is not necessary. to illustrate any stopping mechanism as it will [be understood thatthe rocking of theshaft 5 servesto effect thestopping ofthe knitting machine muster way.

flnerock shaft 5 has fast thereto an. upstanding arm S which is provided in one edge near its upper [end with a through-andj through slot Pivoted to the arm 8 is a drop member 10, said drop member having a laterally entending portion 11 which isnoi mally 'in alignment with theslot-Ql The thread 12 from the bobbin2 extends through 1 agui'de'jeye .13 carriedby thelower end of the arm 8 and fextendsfalong the surface of said arm and acrossthe slot9 as seen Fig. 2. Noriiially the laterally-extending portion 11 of thefdroplnember l0 overlies the-thread;

ber 10 will" be supported thread and [tli'e thread passing between said portion 11 andthe face of thearmf8. Whilefthe machine is running, therefore, thefldrop memg will "be held in thepositionshownirt Figsl l and 2. Iftlie thread l2brealgs or becomesundulyslack it ceases to supportthe dropmeini her 10 and theflatterfalls throughthe slot9 and swings blackwardly Iintojthe; position shownin liifgl3.

means fer accomplishing tliisgfis in the form of a toothed wheel 14 isfast en acon- Means are. provided ,to engage the" drop. member 10 whenit gravitates-into the jposi- .7 tionshown in Fig. 3and thereby to fswingjthe farm 8 forwardlytlius f causing a turning movement of the rock. shaft 5 which "will be "suficient to stop theknitting machine. The.

tinuously-rotating shaft 15 mounted in bearings 16 formed on the supporting arms 7. This shaft 15 is shown as being provided with a driving pulley 17 by which it may be continuously rotated.

The normal position of the shaft 5 and arm 8 during the running of the knitting machine is shown in full lines in Fig. 2 and so long as the thread is intact and is under the proper tension the drop member 10 will be held in its inoperative position shown in full lines Fig. 2 by its engagement with the yarn. lVhen in this position it is out of the path of movement of the teeth oi the wheel 14 so that said wheel is permitted to rotate freely.

When the yarn 12 breaks, however, the drop member 10 will be no longer supported by the yarn and will gravitate into the dotted line position Fig. 2, in which position the laterally-extending portion 11 of the drop member is in the path of movement of the teeth 18 of the toothed wheel 1 1. The stop member will thus be engaged bv one of the teeth and as the wiieel continues LO rotate the stop member will be forced to the right Fig. 2 and will thereby swing the arm 8 from the position shown in Fig.2 to that shown in Fig. 3. This swinging movement of the arm gives the rock shaft 5 a suiiicient turning movement to effect the stopping of the knitting machine.

The same operation will result if the yarn becomes unduly slack. For if the yarn is suiiiciently slack the member 10 will gravitate into the dotted line position Fig. 10 thereby bringing it into position to be engaged by the teeth 18 of the toothed wheel 14.

The invention also provides means whereby the drop wire 10 will be released and thus co-operate with the toothed wheel 14 to stop the machine if the yarn contains a bunch or a knot. Pivoted to the arm 8 at 27 is a swinging knot catcher 26 which is provided with a forked end 28 through which the yarn passes. The slot in this forked end is wide enough to receive the perfect yarn but if the yarn contains a knot so large that it will not pass through the slot the engagement of the knot with the knot catcher 26 will swing it upwardly into the dotted line position. It will be noted that the knot catcher normally occupies a downwardly-inclined position resting on a stop pin 31. The upward swinging movement of the knot catcher into the dotted line position causes the yarn 12 to be moved laterally as shown by dotted lines Fig. 1 and this lateral movement is suficient to carry the yarn out from under the free end of the. laterally-extending portion 11 of the drop wire, thus freeing the drop wire to allow it to fall into the dotted line position Fig. 2 and thereby co-operate with the toothed wheel 14; to stop the knitting machine. This stopping of the knitting machine occurs before the knot has time to reach the knitting point.

My invention also provides means whereby if the yarn becomes unduly taut it will cause the operation of the stop device before the yarn breaks.

To accomplish this I have provided the device illustrated in Fig. 1 and which forms a support over which the yarn passes after it leaves the arm 8 and before it led to the knitting point.

30 indicates a bracket which may be secured in any suitable way to the frame of the knitting machine above the parts shown in Figs. 1, 2 and 3. Pivoted at 31 to the bracket is a yarn-supporting arm 32 over which the yarn 12 passes. This arm is acted on by a spring 33 which normally holds the arm in the operative position shown in Fig. l, a stop 3% being provided to limit the spring-impelled movement of the arm. The free end of the arm 32 operates in a guard loop 35 that is secured to the bracket 34, this guard permitting free swinging movement of the arm but normally holding the yarn 12 from running 0d the arm.

So long as the tension on the yarn is normal the yarn-supporting arm .32'will be retained in its operative horizontal position shown in full lines Fig. 4. If, however, the yarn becomes unduly taut, as might be the case it there was a knot in the yarn which caught on some object, then the strain on the yarn will overcome the spring 33 and will cause the yarn-retaining arm 32 to swing downwardly into the dotted line position Fig. t. When the yz'u'n-retaining arm reaches this position the yarn 12 will slip off from the end of the arm thereby producing in the yarn the necessary slackness which will allow the stop mechanism to work as above described.

When the machine is manually stopped for any reason and no yarn is being drawn from the bobbin'2, there might be a tendency for the weight of the drop wire 10 to pull off snliicient slack from the yarn 2 to permit the drop wire to swing into the dotted line position Fig. 2, in which case when the machine was started up again the stop motion would automatically operate. In order to prevent this I have provided the swinging clamping member 22 pivoted to the arm at 23 and provided with the clamping portion 24 that overlies the yarn 12. So long as the machine is in. operation this clamping member 21 held in inoperative position by a cam projection rigid with the drop wire 10. W hen the drop wire is in the full line position shown i n Fig. 2 the cam projection 25 engages the clamping member 22 and holds the portion 24: out of engagement with the arm 8 but when the drop wire 10 swings backwardly slightly this projection 25 is withdrawn from the clamping member 22 and the latter gravitates into its operative position shown in Fig. 3. In this position thefinger or portion 2 1 thereof engages the yarn and clamps it against the arm 8 thereby applying sufficient tension to the yarn to prevent it from being pulled off from the bobbin by the weight of the drop wire 10. The member 24., therefore, serves to prevent the stopmotion from acting when the machine is manually brought to rest.

The rock shaft and arm 8 are shown as normally held in the position shown in'Figs. 1 and 2 through the medium of a spring 19 which encircles the shaft 5 and one end of which is connected to a bearing 6 and the other end of which is connected to acollar that is fast on the shaft. The spring is arranged to resist the turning movement of the rock shaft 5 from the position shown in Fig. 2 to that shown in Fig. 3 and said shaft will be held in the position shown in Figs. and 2 by the engagement of the arm 4 with a stop pin 21. i

I claim. V a

1. In a stop motion forknitting machines, the combination with a rock shaft adapted by its turning movement to operate a stopping mechanism, a slotted arm fast on the rock shaft, the yarn leading to the knitting point passing acrosssaid slot, a drop member pivoted to the arm and normally supported by the portion of the yarn spanning the slot, whereby when the yarn breaks or becomes un duly slack the drop member will gravitate through the slot into abnormal position, a

constantly-rotating toothed wheel, the teeth of which move in a path traversed ,by the drop member when it gravitates into abnormal position, whereby engagement of the teeth with the drop member will swing the arm forwardly and turn the rock shaft thereby to, operate the stopping mechanism, and means to apply a clamping action to the thread between the drop member and the source of supply when said drop member begins to gravitate into abnormal position; i

2. In a stop motion for the combination with a rock shaft adapted by t its turning movement to operate a stopping mechanism, an arm fast on the rock shaft, a

drop member pivoted to the arm and normally held in elevated position by engagement with the yarn, said stop member gravitatlng into abnormal position when the yarnbreaks or becomes unduly slack, a constantly-rotating toothed. wheel, the teeth of which move in a path traversed by the drop member when it gravitates into abnormal position, whereby the engagement of theteethwiththe drop member will turn the rock shaft to cause the stop mechanism to operate, and aretaining membernormally held in'inop'erative posi tion by thedrop member when the latter is in normal position, said retaining member gravitating into operative position to clamp the yarn against the arm when the drop member starts to gravitate into its abnormal position. n

3. In a stop motion for knitting machines,

tion.

knitting machines,

i the combination with a rock shaft adapted by its turning movement to operate a stopping mechanism, of an arm fast on the rock shaft, a drop member pivoted to the arm and held in elevated position by a normally-tensioned yarn, a constantly-rotating toothed wheel, said drop member when released from the yarn gravitating into abnormal position into the path of movement of the teeth of said toothed wheel, a yarn-clamping member normally held out of engagement with the yarn by the drop member when the latter is in normal position,said clamping member gravitating into clamping engagement with the tating into abnormal position when the yarn breaks or becomes unduly slack, a constantlyrotating toothed wheel, the teeth of which move in a path traversed the drop member when it gravitates into abnormal position, whereby the engagement of the'teeth with the drop member will turn the rock shaft to cause thestop mechanism to operate, a thread-clamping element adapted to apply clamping pressure to the thread between the source of supply and the drop member, and means associated with said drop member to maintain the, thread-clamping element in inoperative position while the drop member is in normal position and to allow'the clamping member to become operative when the drop member moves into an abnormal posi- 5. In a stop motion for knitting machines, the combination with a rock shaft adapted by its turning movement to operate a stopping mechanism, an arm fast on the rock shaft, a

drop member pivoted to the arm andnormal ly held in elevated position by engagement 1 a with the yarn, said stop member gravitating into abnormal position when the yarn breaks or becomes unduly slack, a: constantly-rotating toothed wheel, the teeth of which move in a path traversed by the drop member when it gravitates into abnormalposition, whereby the engagement of the teeth with the drop 'member will turn the rock shaft to cause the stop mechanism to operate, andmeans to ap ply a clamping action to the thread between the drop member and the source of supply when said dropmember begins to gravitate into abnormal position.

In testimonywhereof, I have signed my name to this specification.

DANIEL F.- SULLIVAN. 

